Method of manufacturing tread parts and other similar articles



Nov. 18, 1947.

H. J. KLJNE EF AL METHOD OF MANUFACTURINGv TREAD PARTS AND OTHER SIMILARARTICLES Filed Aug. 7, 1942 3 Sheets-Sheet 1 me/whom.

HERBERT- l HLINE HHTHUH Ll HNHFF Nov. 18, 1947. H. J. KLINE ETAL2,430,986 v METHOD OF MANUFACTURING 'I READ PARTS AND OTHER SIMILARARTICLES Filed Aug. 7, 191,12 3 Sheets-Sheet` 2 H. J. KLINE x-:T A1.2,430,986

METHOD OF MANUFACTURING TREAD PARTS AND OTHER SIMILAR ARTICLES Nov. 1s,1947.

Filgd Aug. 7, 1942 3 Sheets-Sheet 3 f6 HERBERT J ILJNE Patente-d Nov.18, 1947 METHOD OF MANUFACTURING TREAD PARTS AND OTHER SIMILAR ARTICLESHerbert E. Kline and Arthur D. Knapp, Jackson, Mich., assgnors toMechanical Productse Inc., Jackson, Mich., a corporation of MichiganApplication August 7, 1942, Serial No. 454,070

4 Claims. l The present invention relates to improvements in method ofmanufacturing endless tread parts and other similar articles.

this end, the present invention provides an improved method of for-ming.and shaping parts of endless tread used upon trucks and tanks and othersimilar parts capable of being fabricated from steel bars and strips andhaving inter mediate portions thereof of irregular form or increasedthickness.

Thus, one of the objects of the present invention is to provide :a newand improved method of manufacturing metallic parts of endless treads.

Another object of the invention is to provide an improved method ofmanufacturing parts from steel bars and strips having upset portionslocated between the extremities of the parts.

A further object is to provide a method of forming and shaping partsfrom steel bars and strips to provide finished parts having irregularthickened portions in lieu of forging.

These and other objects and advantages residing in the specific detailsof my improved meth* od of manufacture, the structure for carrying outthe improved method, and the resulting articles of manufacture will morefully appear from the following description and the annexed claims,

Referring to the drawings, wherein one form of structure is disclosedfor carrying out the method of manufacture of the present invention,

Fig. 1 is a side elevational view of the forming dies, partially shownin broken vertical cross section, the dotted line representation showingthe die in its upper position,

Fig. 2 is a cross-sectional view taken on line II-II of Fig. 1,

Fig. 3 is a side elevational view, partly shown in broken vertical crosssection, of the one end of the die for forming the end of the treadpart,

Fig. 4 is a side elevational view, partly shown in broken vertical crosssection, of the die shown in Fig. 3 in its up position,

Fig. 5 is a diagrammatic representation of the electrical heatingapparatus for localized heating of the tread parts prior to forming,

Fig. 6 illustrates a work blank from which the tread parts arefabricated,

Fig. 7 shows the inner tread part after the up- (Cl. Ztl-148.3)

setting operation of its central portion in the dies shown in Figs. 1and 2,

Fig. S shows the inner tread part after the end forming operation in thedies shown in Figs. 3 and 4,

Fig. 9 shows the inner tread parts following milling and drillingoperations,

Fig. l0 is a plan view of a work blank correspending to that of Fig. 6of slightly less length, following an upsetting operation in diescorresponding to those shown in Figs. l and 2, but of different shapeand contour,

Fig. 11 is a cross-sectional view taken on line XI-XI of Fig. l0,

Fig. 12 is a plan view of the outer tread part following machining,

Fig. 13 is a fragmentary View showing the upper and lower tread partsassembled, partially shown in broken vertical cross section, and

Fig. 14 is a perspective View shown in vertical cross section of aportion of endless tread showing the upper and lower tread partsembedded in rubber.

In Figs. 1 to 4, inclusive, are shown suitable dies for carrying out themethod of manufacture on the work blanks shown in Figs. 8 and 10.Preferably, these work blanks are fabricated from a strip of steel asshown in Fig. 6 of uniform cross section cut to the correct length andindicated by reference .character Ill. For convenience of description, apartly finished inner tread element shown in Fig. '7 is indicated byreference character l2 following the iirst upsetting operation in thedies of Figs. 1 and 2, by reference character I4 in Fig. 8 following theend forming operation in the dies of Figs. 3 and 4, and by referencecharacter l5 in its finished form in Fig, 9.

The finished outer tread part of Fig. 12 is indicated in Fig. 10 byreference character I8 following the operation in dies corresponding tothose of Figs. l and 2, and by reference character 20 in its nished formas shown in Fig. 12.

Referring to Figs. 1 and 2, the Work blank I2 of Fig. 7 has been formedby the dies which are Shown in full line in their closed position. It isto be understood that a work blank corresponding to the blank iii ofFig. 6 was first inserted into the dies of Figs. l and 2 with the samein their open and dotted line positions, and that the blank l2 wasformed upon the dies moving into their closed full line position.

The dies of Figs. 1 and 2 comprise an upper die shoe 22, and a lower dieshoe 24 having back up blocks 26. Supported in the upper die shoe l2 arecams 28 having angularly disposed cam surfaces 38 which wipe acrosscomplementary surfaces 32 of the cam blocks 34. Guides 38 support thecam blocks 34 for horizontal movement toward and away from each otherwith springs 3'I holding the inclined surfaces 38 and 32 in contact witheach other when the upper die shoe carrying the cams 28 is raised andlowered.

The lower die 38 has a channel 48 corresponding substantially in depthand Width to that of the work blank IIJ of Fig. 6. Carried within thelower die 38 is an inserted die form 42 having a cavity 44 correspondingin shape and contour to the central portion 48 of the blank I2 of Fig.'1.

The pressure pad 5I) is carried by the upper die shoe 22 through guides52 and 54. Shoulders 56 and 58 limit the extended downward posiltion ofthe pressure pad 58 with the upper die shoe in its raised position asshown in dotted outline. Pockets 88 and 82 denned in the pressure padand the upper die shoe respectively support compression springs 84 in a,well-known manner. The punch E6 is supported in the upper die shoe 22and is projected during operation of the press through the bore 88defined in the pressure pad 58. As more clearly shown in Fig. 2, whenthe upper die shoe 22 has been lowered during the operation of thepress, the pressure pad 58 is supported upon the lower die 38, bridgingthe channel 48 to completely support the work vblank in all directionsagainst bodily movement except in an axial direction.

In Fig. 5, the work blank I8 of Fig. 6 is shown clamped betweenelectrodes 'I8 of a resistance heating unit to heat the central portionbetween the lines 'I2 and "I4 (see Fig, 6) to a relatively hightemperature. In practice, this temperature may run up to 2200o F. and asshown in Fig. 5 the heating is controlled through a photoelectric cellI5 operating a circuit opening relay '11, all of well-knownconstruction. In practice, the heating of the central portion I8 of theblank I8 is so rapid that the ends 78 remain substantially at roomtemperature and are cool enough to permit bare hand handling fortransferring the work blank I8 from the resistance heater to insert itin the groove 48 of the lower die 38 in position so that the extremities88 of the Work blank IU are engaged by the shoulders 82 of the camblocks 34. Movement of the upper die shoe from the dotted line positionshown in Fig. l toward the full line position rst results in thepressure pad 50 engaging with the lower die 38, building up sucientpressure to conne the work blank I0 against movement in any direction inthe groove 48 except axially. As the cams 28 engage with the cam blocksS4, the latter move inwardly toward each other, bringing the shoulders82 against the extremities 88 of the blank III. As the upper die shoe 28continues downwardly, the inward movement of the cam blocks 34 istransmitted to the end portions 'I8 of the work blank, upsetting theheated central portion I6 into the cavity 44 of the inserted die form42. Preferably, the movement of the upper die shoe 22 is so regulatedthat its iinal movement downwardly fully advances the punch 88 andsufficiently advances the cam block 34 to complete the upset of thecentral portion 48 and ll the cavity 44. In practice, the advance of thecam block 34 is regulated to provide a slight flash of metal between thedies defining the cavity 44. This will take care of slight variations inthe length of the work blanks I8. By keeping the dies defining thecavity 44 in good condition and the length of the work blanks IIJ toclose limits, it is possible to upset the central portion 48substantially to nished dimensions and without appreciable iiash.

The Work piece I2 of Fig. 'l is formed in the manner just described bythe forming dies of Figs, 1 and 2. To produce the work piece I4 of Fig8, the piece I2 is placed on the forming dies of Figs. 3 and 4 to turnup and form the ends 84. In Fig. 3 the forming dies are shown closedwhile in Fig. 4 the work piece I2 is shown in position prior to closingthe dies forming the ends 84. The lower die shoe 88 carries the lowerdie 88 which is channeled in the manner of the die 38 of Fig. 2. Anupper die shoe 98 is movable and carries a cam 92 which actuates the camblock 94. Also supported from the shoe SII is a pressure pad 86supported for vertical movement in guides 88 upon compression andexpansion of the springs |88. Fixed to the under side of the pressurepad 95 are spaced ram guides |82 which support the ram |04 forhorizontal movement. At the outer end oi the ram |84 is a replaceableforming nose |88. Springs |88 retract the ram |04 to bring the shoulderI IIJ against the stop I|2 of the guides |02 as shown in Fig. 4.Referring to Fig, 3, the end ||4 of the ram |84 is acted upon by the camblock 84 to impart the necessary horizontal movement to the ram |04. Asshown in Fig. 4, the die 88 is provided with a recess IIB having spacedprotuberances I8 for the forming of the recesses |28 of Fig. 8.

To form the ends 84 of the work piece I4, the ends of the work piece I2are preferably heated over the distance as indicated at X in Fig. 4.With the work piece I2 positioned as shown in Fig. 4, the portion |22 ofthe ram nose Ibends the end which overhangs the recess IIS downwardly.As the shoe 98 continues its downward movement it brings the pressurepad 88 into a position conning the work piece I2 in the channel 24. Thenal movement oi the shoe iniparts a slight amount of horizontal movementto the ram no-se bringing the rain nose |88 into the position shown inFig 3 to complete the form'- ing of the ends 84 of Fig. S. A linger |25holds the work piece in position at the time the nose bends the enddownwardly.

In Fig. 9, the work piece I4 of Fig. 8 is shown nnished as the innertread part I8. The central portion 48 has been pierced at |28, milled tothe contour shown, drilled at grooves |38 milled along the inner face|32.

The outer tread part I8 of Figs. l0 and li is formed by upsetting thecentral portion |34 from a work blank I8 of Fig. 6. Preferably, theupsetting and forming of the central portion |34 is carried out in theforming die c1 Figs. l and 2 with the appropriate shaped die 42 andpunch IIS. In Fig. 12, the part I8 of Figs. l0 and ll is shown as thefinished outer tread part 28, the hole |36 having been pierced,the'holes 38 drilled and the cross grooves |48 milled.

Referring to Fig. 13, the inner and outer tread parts I6 and 28 areshown assembled upon each other, with the grooves |38 and I 48collectively dening passages |42. In Fig. 14. the tread parts are shownembedded in the continuous rubber tread |44 with the cables |48 passingthrough the passage denned by the cross grooves |38 and |48.

Having thus described our invention, what we desire to protect byLetters Patent and claim is:

l. A manufacturing method of simulating a forged metal part havingintermediate portions of increased cross-sectional dimensions from ametal blank of uniform cross-section, comprising the steps of cuttingthe blank to a length greater |28, and the cross` than the desiredlength of the finished part, heating certain portions of said blank torelatively high temperature while maintaining other portions thereof atrelatively low temperature, conning the portions maintained atrelatively low temperature against movement in all directions exceptaxial, embracing portions of said blank having relatively hightemperature in a cavity having clearance with the blank in a radialdirection, upsetting said heated portions into said cavity through axialmovement of said lower temperature blank portions through pressureapplied inwardly axially thereof to form an enlarged and thickenedportion, piercing said enlarged portion, and machining the thick andthin portions of said blank to the desired finished shape of the metalpart.

2. A manufacturing method of simulating a forged metal part havingintermediate portions of increased cross-sectional dimensions from ametal blank of uniform cross-section, comprising the steps of cuttingthe blank to a length greater than the desired length of the nishedpart, heating middle portions of said blank to relatively hightemperature while maintaining end portions thereof at relatively lowtemperature7 confining the end portions against movement in alldirections except axial, embracing the middle heated portions of saidblank in a cavity having clearance with the blank in a radial directionand having the cavity provided with enlarged clearance portionscorresponding substantially to the general form of enlarged ribs desiredon the iinished blank, upsetting said heated portions into said cavitythrough axial endwise pressure exerted inwardly upon the ends of saidblank of lower temperature, thereby enlarging the blank in ribsextending lengthwise thereof by thickening the material through itslesser dimension, and thereafter machining the thick and thin portionsof said blank to the desired finished shape of the metal part.

3. A manufacturing method of simulating a forged metal part havingintermediate portions of increased cross-sectional dimensions from anelongated flat metal blank of substantially uniform cross-sectionthroughout its length, comprising the steps of cutting the blank to alength greater than the desired length of the finished part, heatingmiddle portions of said blank to relatively high temperature,maintaining other portions thereof toward the ends at relatively lowtemperatures, confining the portions maintained at relatively lowtemperature against movement in all directions except axial, embracingthe heated portion of said blank in a cavity having lateral clearancecorresponding substantially to the desired nished shape of the part,upsetting said heated portion into said cavity through axial inwardendwise pressure applied to the lower temperature blank portions therebyenlarging said blank transversely of its greater dimension, piercingsaid enlarged portion, and machining the blank to the desired finishedshape of the metal part.

4. A manufacturing method of simulating a forged metal part havingintermediate portions of increased cross-sectional dimensions from anelongated metal blank having substantially uniform cross-section,comprising the steps of cutting the blank to length greater than thedesired length of the nished part, heating middle portions of said blankto relatively high temperature while maintaining end portions thereof atrelatively low temperature, confining the portions maintained atrelatively low temperature against movement in all directions exceptaxial, embracing heated portions of said blank in a cavity havingclearance with the blank in a radial direction, with the cavitycorresponding substantially to the shape of enlargements desired in thefinished part, upsetting said heated portions into said cavity throughpressure applied axially inwardly upon the portions maintained atrelatively low temperature, thereby forming an enlarged and thickenedportion, upsetting and shaping the ends of the blank, piercing desiredportions of said blank, and machining the thick and thin and shapedportions of said blank to the desired finished shape and dimensions ofthe metal part.

HERBERT J. KLINE. ARTHUR D. KNAPP.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,668,442 Wineman May 1, 19282,314,574 Dickerman Mar. 23, 1943 2,066,186 Mitchell Dec. 29, 19362,272,425 Nettenstrom Feb. 10, 1942 1,952,545 Gotshall Mar. 27, 19342,037,415 Heaslet Apr. 14, 1936 2,039,012 Lindberg Apr. 28, 19362,067,269 Johnson Jan. 12, 1937 2,025,999 Myers Dec, 31, 1935 1,397,314Cox Nov. 15, 1921 1,632,674 Pearson June 14, 1927 1,517,716 DutkiewiczDec. 2, 1924

